Superheater support



March 3, 1936. F. HA L SUPERHEATER SUPPORT Filed Feb. 15, 1934 /ZINVENTOR Fe'aps/e/c HALL BY v ATTORNEY Patented Mar. 3, 1936 UNITEDSTATES PATENT OFFICE SUPERHEATER SUPPORT Application February 15, 1934,Serial No. 711,381 In Great Britain February 21, 1933' 6 Claims.

This. invention has reference to steam superheater elements of the kindcomprising a plural-- ity of lengths of pipe, usually four lengths,arranged in a-group and parallelly disposed and extending into a smoketube of a locomotive or like boiler and the invention relatesparticularly to means or devices for holding the constituent pipes of anelement in their correct relation to one another and for supporting theelements in the 10 smoke tubes. For convenience of reference in thisspecification such means or devices will be. designated as element bandsand supports.

Various forms of element bands and supports have been proposedheretofore and certain of the proposals have been carried into practice.The construction of element band and support most largely employed inpractice consists of two strips of metal bent to shape, the one toprovide a spacing member with pipe seats between the pipes of theelement and the other to provide a surrounding band to hold the pipes inposition against such spacing member, the spacing member being rivetedto the band intermediate the ends thereof and the ends of the band beingriveted to one another, appropriately formed and positioned steel blocksor feet being riveted to the band.

The present invention has for its object an im-' proved construction ofelement band and support which shall not only be relatively cheap tomanu- 301 facture, but also: shall be such that it will be robust and ofa form permitting a more ready cleaning or removal from the surfaces ofthe element and flue tube of soot and other deposited furnace products,while, in addition, being such that there will be less liability ofchoking of the flue tube at the support by deposits of soot or the likeon or about the parts of the support.

It is another object of the invention to provide an element band whichshall have the greatest 40 possible amount of its length in contact withthe periphery of the pipes of the element, and thus avoid any relativelylong portions of the band being out of contact with fluid cooledsurface. Thus the band will be efficiently cooled and the liability ofit being burnt out will be reduced.

According to the present invention the element band is formed of asingle strip of metal, such for example as mild "steel, bent to shape toprovide pipe embracing portions or seats, one for each pipe of theelement, the pipe embracing portions when the band is in place on theelement each. exceeding one-half of a cylinder and alternating in thelength of the band with the pipe embracing portions or seats are pipespacing portions or bridges, the ends of the strip after the band hasbeen closed on the element being secured together and serving to spacetwo pipes of the element.

An element band according to this invention may be provided withappropriate feet for sup- 5 porting the element in the smoke tube, andsuch feetmay be separately formed and secured to the element band or maybe formed by bending or folding up the metal strip from which the bandis formed. Preferably the feet would be riveted to internal spacing.member is avoided, as is also 20.

the riveting of the said spacing member to the strip.

The band according to the present invention is placed on the elementafter the several lengths of pipe comprised in the element have beenunited 25 by the return bends to form the complete element, the saidpipes being gripped by an appropriate machine or means while the bandand support are being applied thereto.

A band and support for a four-pipe element, 30 which. is the type ofelement now most largely employed in superheaters for locomotiveboilers, is shown in the accompanying drawing and will be describedhereinafter as an example of an embodiment of the invention: it is to beunder- 35 stood that the invention is not restricted to bands, or bandsand supports, for four-pipe elements, as bands and supports may be madeaccording to the invention for elements comprising a lesser or a greaternumber of parallelly dis- 40 posed pipe lengths in the flue tube.

In the accompanying drawing,

Fig. 1 shows in elevation an element band and support for a four-pipeelement, the band being shown in the shape it takes before it is appliedto the pipes of the element,

Fig. 2 is a view showing the band illustrated in Fig. 1 applied to thefour pipes of a locomotive superheater element disposed in a flue tube,

Figs. 3, 4, and 5 are fragmentary sectional views, the sections beingtaken on the lines 33, 4-4, and 5-5 respectively of Fig. 2 and lookingin the directions of the arrow points, and

Figs. 6,, '7 and 8 are fragmentary views illus- 55 one-half of acylinder and forming, for example, approximately three-quarters of acylinder, the

pipe seats I 4 alternating with bridges 5, 6, and 1 forming pipe spacingportions, These three bridges are formed in bending the strip, andafourth bridge is formed, after the strip has been placed on the elementpipes and closed down thereon, by welding a fillet 8between the endportions 9 and III of the strip, the end portions thus being securedtogether. The bridges 5, 6, 1 formed between the pipe seats by bends inthe strip,

preferably have their rigidity increased in some appropriate manner. Asshown in Figs. 1 to 4 the bridges are stiffened by forming across eachbridge one or more depressions II in the metal after the manner ofcorrugations.

Alternatively the bridges may be strengthened as shown in Fig. 6 bydeposits I2 of welding metal in the recesses of the re-entrant portionsbetween the pipe seats.

.In Fig. 2 of the drawing, I3, I4, I5, and I6 are the pipes of asuperheater element, I! being the smoke tube in which the said pipes aredisposed. As in the usual four-pipe locomotive elements, the spacebetween the lower pipes I4, I5 is greater than the spaces between suchpipes and the upper pipes I3, I6 respectively, and also is greater thanthe space between the upper pipes themselves. Consequently, the bridge 6of the band which lies between the lower pipes I4 and I5 and which ismid-way of the length of the strip will be wider than the other bridges5 and I. If desired, such wider bridge 6 may be strengthened bydepressing or corrug-ating the metal whilst the narrower bridges 5, Imay be strengthened by deposits of weld metal as described withreference to Fig. 6.

Where deposits of weld metal are employed to stiffen or reinforce thebridges of the element band such deposit of weld metal may be effectedeither before or after the band is fitted on the element.

In manufacturing the element band shown in Fig. 2 the strip is bent toform the bridges 5, 6, and I and to partially shape the seats or pipeembracing portions I 4 for the pipes, the end portions of the stripbeing left extending towards one another so that the band hasapproximately the form shown in Fig. 1. In applying the band to theelement the bridges or spacing portions 5 and I of the band are forcedinwardly to close the band 'over the lower pipes I4, I5 of the element.Thereafter the end portions 9, III are bent or hammered over so that theupper pipe embracing portions or seats I and 4 are closed on to pipes I3and I6 and the band snugly embraces the respective pipes. Between theend portions 9 and II) which are themselves dependent between the upperpipes I3, I6, the fillet 8 which is preferably somewhat wedge-shaped incross-section, is driven into place and its upper portion welded to theadjacent portions of the band as at I8. A unitary structure is thusformed, which securely holds the pipes in correct relation to oneanother, but which presents a relatively small obstruction to thepassage of combustion gases through the smoke tube.

Usually the element band will be provided with feet to support theelement in position in the smoke tube II. In the band shown in Figs. 1and 2 separately formed solid feet H! are attached to the outer side ofthe portions 2, 3 of the band of the band embracing the lower pipes I4and I5 of the element substantially mid-way between the respectivebridges 5, 6, I. Preferably the solid feet are rivetted to the band asindicated in Figs. 1, 2, and 5, but if desired they might be welded 'tothe band, or be both riveted and welded thereto. Each foot I9 mayconsist of a single block of metal of appropriate dimensions, butconveniently it comprises a main or face portion adapted to contact withthe flue tube and an intermediate packing or filler piece 20 as clearlyshown in Fig. 5. Thus by varying the thickness of the piece 20 thespacing of the pipe from the inner surface of the flue tube maybe'varied.

The foot I9 shown in Fig. 5 is of greater length? than the width of thestrip so that it projects at either side of the strip or band and itssurface U-shape, as shown at 2I in Fig. 6, to provide feet which willgive a substantial bearing surface on the flue tube. To render the feet2| rigid and prevent the band opening out at the bent por tions formingsuch feet, one or more depressions or corrugations 22, similar to thedepressions II' in the bridges 5, 6, are preferably formed in each bentportion 2|.

While it is considered preferable to employ the separate fillet 8 forcompleting the bridge between the pipe embracing portions I and 4 of theband, one extreme end portion of the strip may be folded back on thestrip as shown at 23, Fig. 7, so that when the end portions of the stripare driven into the space between the pipes I3 and I6, the folded backportion 23 will take the place of the fillet 8. The portion 23 would bewelded to the pipe embracing portions I and 4 in a similar manner asdescribed in relation to the fillet 8. If the spacing of the pipes I3,I6 is relatively wide both ends of the strip may be folded back and thefolded back portions welded to one another and to the respective pipeembracing portions.

Where it is desired to secure the ends of the strip to one another byriveting, a strip of greater length may be employed than where the endsare secured together by welding; the end portions of the strip may bebent or folded back on themselves so that when the folds are forced, asby hammering, into position between the two upper pipes the extreme endportions of the strips project upward and lie snugly against one anotherin position to be rlvetted together.

Where it is desired to increase slightly the grip of the bands on thepipes the pipe spacing or bridge portions 5, 6, and 1 may be carriedfurther towards the centre of the band. In this case the ends of suchportions may have a somewhat bulbous appearance as shown at 24, Fig. 8.It will be appreciated that to place a band so formed on the element thepipes would have to be sprung apart in forcing the bridges into positionto allow the bulbous end portions to pass between the pipes. A bridgeformed in the manner shown in Fig. 8 may be strengthened by thedepression II as described with reference to Figs. 1 4, or by a depositof welded metal as described with reference to Fig. 6.

In order to maintain the element band and support according to thepresent invention in position longitudinally of the element smalldeposits or spots of welding metal may be made on one or more of thepipes of the element at opposite sides of the band, but at a suflicientdistance therefrom to prevent the band being united by welding to thepipe or pipes.

The element band according to the present invention is more particularlyintended for use with a four-pipe element, but, as already indicated,bands comprising seats for three pipes only or for more than four pipesmight be formed by bending a single strip of metal substantially in themanner herein described, and securing the ends of the strip together.

Other modifications might be made without departing from the invention.

What I claim is:

1. A band for steam superheater elements of the kind indicatedconsisting of a strip of metal bent to provide four pipe embracingportions alternating in the length of the strip with pipe spacingportions, each pipe embracing portion when the band is in place on thepipes 01' the element exceeding one-half of a cylinder and the ends ofthe strip after the band has been placed on the element being securedtogether and spacing two pipes of such element.

2. An element band as claimed in claim I having the spacing portionsbetween the pipe seats reinforced.

3. An element band as claimed in claim 1 having at least one of thespacing portions stiffened by forming across it a depression after themanner of a corrugation.

4. An element band as claimed in claim I having at least one of thespacing portions stiffened by depositing welding metal in the recessesof the re-entrant portions of the band between the pipe embracingportions thereof.

5. An element band as claimed in claim 1 having a metal filler pieceinserted between the end portions of the strip after they have beenpositioned between the appropriate two pipes of the element, the endportions and filler being welded together.

6. An element band as claimed in claim I having a relatively shortportion at one end of the strip folded back on the strip, thefolded-back portion after the end portions of the strip have been driveninto position between the appropriate two pipes, being welded to theadjacent portions of the strip.

FREDERIC HALL.

